Vízügyi Közlemények, Kivonatok, 1965

Dégen Imre: Az 1965. évi dunai árvíz és árvízvédelmünk fejlődése

(28) distance of 20 m and on the riverside for 10 metres. Along the flood levees and on the crest thereof roads of stabilized soil, or with surface treatment are necessary. One of the most important prerequisites of successful flood defense is observation and reconnaissance and in this respect every preparation must be made. The problems to be solved for developing the flood control system to a higher standard of safety were demonstrated by the flood and the trends for further research are set. The development program of flood control is contained in the Perspective Plan for Water Resources Management. It is envisaged therein to develop the system of levees to offer safe protection against 100 year Jrequency floods (Fig. 20). For this purpose the earth volume of levees must be increased by 25 %. Rather than the construction of new flood levees, the main task consists of strengthening existing levees, raising their crest, improving the levee cross-section and thus seepage characteristics. Instead of the existing standard berm cross section, full sections with changing slope inclinations are contemplated, as these appear to be superior in every respect (Fig. 19). Along the Danube levees underseepage proved to be the main source of danger, and thus special care must be devoted to methods suitable for reducing uplift pressures acting on the topcover. An important step in the development of flood control structures in the Danube Valley is the construction of the tailworks of the Sio Canal, which would prevent the entrance of floodwaters into the 36 km long backwater reach of the canal. The construction of the flood gate in the mouth of the Danube-Valley Main Canal is also envisaged for the next five-year plan period. * * * Values amounting to several thousand million Forints were saved from destruction by flood defense works carried out in the Danube Valley. Nevertheless, flood damages were considerable. Direct flood damage in the inundated flood plain and highbanks — which were not protected by levees — amounted to 360 million Forints. Waters rising landward from the levees covered 17.000 hectares of fieldland and damaged 2600 homes. Annex: SEQUENCE OF EVENTS DURING THE 1965 FLOODS IN WESTERN TRANSDANUBIA, ON THE DANUBE AND FLOOD CONTROL OPERATIONS (For the Hungarian text see 46).